Steatocystoma multiplex: keratin 17 - the key player?

Sonographic Appearance of Steatocystoma: An Analysis of 14 Pathologically Confirmed Lesions

Purpose

To evaluate the ultrasonographic characteristics of steatocystomas focusing on the features that aid in differentiating them from epidermal inclusion cysts and lipomas.

Materials and Methods

The ultrasonographic findings of 14 histologically proven steatocystomas in 10 patients were retrospectively reviewed. The following features were assessed: the layer of involvement, shape, margin, echogenicity, posterior acoustic features, and the presence of a visible wall or intralesional striations. The findings were compared with those of subcutaneous lipomas and epidermal inclusion cysts to identify those findings that aid in the differential diagnosis of steatocystomas.

Results

The majority of steatocystomas appeared as a subcutaneous mass (n = 6, 42.9%) or a mass involving both the dermal and subcutaneous layers (n = 6, 42.9%). Steatocystomas exhibited a well-defined smooth margin (n = 12, 85.7%) and homogeneous echogenicity (n = 9, 64.3%), and showed no specific posterior acoustic features (n = 9, 64.3%). The most important features that differentiated steatocystomas from epidermal inclusion cysts were a homogeneous internal echotexture (p = 0.009) and absent or less prominent posterior acoustic enhancement (p < 0.001). The features that distinguished steatocystomas from lipomas were the margin (p < 0.001), echogenicity (p = 0.034), internal echotexture (p = 0.004), and the absence of intralesional striations (p < 0.001).

Conclusion

Steatocystomas appeared as well-defined homogeneous masses with mild or absent posterior acoustic enhancement.

Steatocystoma Multiplex Suppurativa: A Case with Unusual Giant Cysts over the Scalp and Neck

Steatocystoma multiplex (SM) is a rare hamartomatous malformation of the pilosebaceous duct junction. Most cases of SM are sporadic, although less common autosomal dominant inherited forms have been reported. Steatocystoma multiplex suppurativa (SMS) is a much rarer inflammatory variant of SM, associated with severe inflammatory lesions resembling those of hidradenitis suppurativa. We describe herein a 28-year-old male with SMS who presented with extensive giant cysts on his neck, face, and scalp.

A Tale of Two Cysts: Steatocystoma Multiplex and Eruptive Vellus Hair Cysts—Two Case Reports and a Review of the Literature

Background. Steatocystoma multiplex (SM) and eruptive vellus hair cysts (EVHC) are uncommon benign tumors of the pilosebaceous unit. Both SM and EVHC are characterized by smooth, asymptomatic papules or nodules, most commonly presenting on the chest, limbs, and abdomen. Most cases of SM and EVHC are sporadic, although less common autosomal dominant inherited forms have been reported. Main Observation. In this report we present two cases of cutaneous cysts exhibiting characteristics of either SM or EVHC. Both patients presented with numerous 1-2 mm asymptomatic papules and responded well to surgical expression by incision and drainage (I&D). Conclusion. SM and EVHC are similar in clinical presentation and management. Previously reported “hybrid-type” tumors present strong evidence for a relationship between the two lesions pathologically. Due to potential similarity of EVHC and SM cyst contents, I&D and subsequent microscopic examination cannot definitely differentiate between EVHC, SM, and hybrid cysts.

Steatocystoma multiplex with hair shaft abnormalities

Steatocystoma multiplex (SM) is an unusual benign disorder of the pilosebaceous duct characterized by multiple cysts with little or no nail and hair involvement. We report a 30-year-old woman with multiple cystic nodules located on the neck, axillae and forearms as well as patchy scalp alopecia. Histopathological examination of the lesions was diagnostic of SM. Trichoscopy revealed pili torti and pili canaliculi. This patient represents an unusual clinical presentation of SM because of the presence of hair abnormalities.